Democratic Sen. Tim Kaine of Virginia is demanding that a secret memo that describes President Trump’s interpretation of his legal authority to declare war be released, according to a report.

Kaine, a member of the Armed Services and Foreign Relations committees, urged Secretary of State Rex Tillerson in a letter late Thursday to release the seven-page document, NBC News reported.

The Trump administration has kept the memo under wraps for months, according to the news outlet.

“The fact that there is a lengthy memo with a more detailed legal justification that has not been shared with Congress, or the American public, is unacceptable,” Kaine wrote in the letter, which NBC News obtained.

“I am also concerned that this legal justification may now become precedent for additional executive unilateral military action, including this week’s U.S. airstrikes in Syria against pro-Assad forces or even an extremely risky ‘bloody nose’ strike against North Korea,” he continued.